https://wccftech.com/ipad-pro-magic-keyboard-usb-c-passthrough-port-allows-charging-speeds-of-up-to-22w/

The Magic Keyboard for iPad Pro features a USB-C passthrough port and it allows you to charge the tablet at a fairly respectable 22 watts.

Announced alongside the 2020 iPad Pro, the new Magic Keyboard is an accessory that brings Apple’s tablet closer to a real computer, although it still has a long way to go. The Magic Keyboard has scissor switches for an exceptional typing experience, a trackpad to take advantage of Apple’s newly added mouse features to iPadOS, and a passthrough USB-C port for charging.